Heat Loss Indicator
A Heat Loss Indicator (HLI) is a metric or tool used to assess the rate at which heat escapes from a building, system, or object. It’s commonly applied in the context of energy efficiency, particularly for homes or buildings, to evaluate how well they retain heat and identify areas where insulation or structural improvements might be needed.
Thermal conductivity of materials (how easily heat passes through walls, windows, roofs, etc.).
Surface area exposed to the outside environment.
Temperature difference between the inside and outside.
Air leakage (drafts or poor sealing).
For example, in building energy assessments (BER Reports), heat loss is calculated in watts per square meter per degree of temperature difference (W/m²·K). A lower value indicates better insulation and less heat loss, while a higher value suggests inefficiency.
U-Values
A U-value (also known as thermal transmittance) is a measure of how effective a material or building component (like a wall, window, or roof) is at preventing heat from passing through it. It’s commonly used in construction and engineering to assess insulation properties. The lower the U-value, the better the material is at insulating, meaning less heat is lost.
- Units: Typically measured in watts per square meter per kelvin (W/m²·K).
- Example: A well-insulated wall might have a U-value of 0.2 W/m²·K, while a single-pane window might have a much higher U-value, like 5.0 W/m²·K, indicating it’s less efficient at retaining heat.
The HLI & U-Value will form part of your custom retrofitting plan. Call our expert team to start your retrofitting journey today.
